Members of the Molecular Biology and Chemistry Departments at the University of Wyoming seek to significantly extend and enhance our present mass spectrometer. The request includes an atmospheric pressure spectrometry facilities by acquiring an electrospray mass pressure ionization (API) source, and electrospray probe, an atmospheric pressure chemical ionization (APCI) probe, a gradient liquid chromatography system with a diode array detector, and spectral analysis software. The electrospray mass spectrometer will add significant new and vital capabilities to our analytical facilities at the University of Wyoming. Currently these facilities do not exist at this or any other institutions in the State of Wyoming. This Proposal seeks funds to purchase a new bench top reliable unit that will suit our needs for many years to come. A main user group of four NIH funded scientists has been identified and the applications of electrospray mass spectroscopy to their research are described in detail below. In addition, a second group of users have been identified and short letters of interest have been collected in the appendix. Altogether, a modestly priced instrument is requested to meet the needs of these researchers who will benefit enormously from this heretofore unavailable tool on our site.